Steam-engine



(No Model.)

A. F. HALL.

STEAM ENGINE. No. 347,344. Patented Aug. 17, 1886.

A {w shun gym UNITED STATES PATENT OFFICE.

ALBERT F. HALL, OF BOSTON, MASSACHUSETTS.

STEAM-ENGINE.

"JPECIFICATION forming part of Letters Patent No. 347,344, dated August 17, 1886.

Application filed December 14, 1885. Serial No. 185.600. (No model.)

To all whom it may concern.-

Be it known that I, ALBERT F. HALL, of Boston, county of Suffolk, and State of Massachusetts, have invented an Improvement in Steam-Engines, of which the following description, in. connection with the accompanying drawings, is aspecification, like letters on the drawings representing like parts.

directly from the boiler or generator or reservoir ot' actuating-fluid, and the fluid, after having done its work in the smaller or highpressure cylinders, is exhausted into the larger or'low pressure cylinders, either passing directly thereto, or passing into an intermediate chamber or receiver and then to the larger cylinders, from which it is finally exhausted into the atmosphere or a consumer.

The object of the present invention is to provide means by which the power ofa duplex engine may be increased,it' necessary; and the invention consists,essentially,in providing an exhaust-passage for the smaller or high-pressure cylinders, independent of the inlet-passage for the low-pressure cylinder, the said independent exhaust-passage leading to the atmosphere or condenser, and also providing an independent passage for the actuating-fluid, which will, for convenience, be called live steam, to enter the larger or low-pressure cylinders with its initial pressure,together with a suitable valve or valves for controlling the said passages. When the duplex pumpingengine is to operate as a compound engine, the live-steam or induction passage from the boiler to the larger cylinders is closed, the independent exhaust-passage from the smaller cylinders is also closed, and.the passage from the receiver or exhaust of the smaller cylinders to the inlet of the larger cylinders is open; but when it is desired to increase the power of the engine the passage'from the receiver or exhaust of the smaller cylinders to the inlet of the larger cylinders is closed, and the independent exhaust for the said smaller cylinders is opened and the inlet for live steam to the larger cylinders is opened, so that the two pairs of cylinders practically constitute two pairs of independent simple engines, each cylinder of each pair receiving steam or other fluid at full pressure and exhausting itin the usual manner.

Figure l is a plan view of a duplex compound pumping-engine embodying this invention; Fig. 2, a side elet ation thereof; Fig. 3, an end elevation thereof, and Fig. 4 a diagram indicating the relations of the different passages and valves therein to the diiferent cylinders of the engine.

The engines A A may be of any suitable or usual construction-for instance,substantially the same as shown in Letters Patent No. 270,575, dated January 16, 1883, the piston of one engine controlling the valves of the other by mechanism not shown, as it forms no part of the present invention.

Each engine comprises two cylinders, a a, the former of smaller diameter than the latter, the said cylinders being intended to normally co-operate together as a compound engine, the smaller or high-pressure cylinder at taking steam through the main steam-inlet b b from the boiler at one side of the piston, and exhausting the steam which has previously done its work at the other side of the piston, through a pipe, 0, (see Figs. 2 and 3,) into a receiver, 0, from which it is taken by pipe d d to the larger or low-pressure cylinder a, in which it operates on the piston in the same direction that the live steam operates in the smaller cylinder, a, the piston'rods e e from the two cylinders (see Fig. 1) being connected with a single cross-head, so that the steam in both the cylinders a a works in unison in overcoming the load of the engine. The steam that has done its work in the two cylinders successively, as described, is exhausted from the larger cylinder through the exhaust-pipe, f f and the parts thus far described, operating in the manner set forth, are the same as usually found in compound engines, and are would be exactly the same whether one or two engines were used.

In order to enable the engine to exertgreater power than it can inits normal operation as a compound engine, it is, in accordance with the present invention, provided with a branch pipe, Z)", (see Figs. 2 and 3,) from the main steam-supply pi pc I), leading to the inlet-pipe (Z of the larger eylindeiy through which the steam normally taken from the receiver 0, or exhausting from the smaller cylinder, passes to the larger cylinder, the said pipe If containing a stop-valve, 11, having a handle, It, Said valve normally, when the engine is aeting as a compound engine, being closed. The pipe (Z, leading from the receiver a to the inletpipe (1 of the large cylinder, is also provided with a stop-valve, 1', having a handle, i3, and when increased power is desired the said valve 1' is closed and the valve h opened, so that the steam admitted to the large cylinder a comes directly from the pipe I) at the full initial pressure, instead of being taken from the receiver c after having exhausted from the smaller cylinder,u, and thus having expanded and had its pressure reduced. As the exhaust from the small cylinder a no longer passes to the large cylinder under the conditions last named, means must be provided for removing the exhaust-steam from the said small cylinder, and for this purpose the receiver 0, or other exhaust passage or receptacle through which the steam passes from the small cylinder, is connected by pipe on with the main exhaustpassuge f from the larger cylinder, the said pipe on containing a stop-valve, it, having a handle, a, which valve is normally closed when the cylinders are operating as a compound engine, but which is opened to permit the exhaust lrom the smaller cylinder to escape when the larger cylinder is taking its supply of steam from the boiler or prime source, instead of from the receiver.

The diagram, Fig. 4, shows the valves in full lines in the position occupied when the engine is operating a compound engine, and the full-line arrows show the direction of the tiow of steam under these conditions, the double-headed arrows representing exhaust steam or fluid from the smaller cylinder, and the triple-headed arrow representing steam that has been used in the two cylinders successively.

The dotted-line position of the valves and the dotted arrows indicate the condition when the two cylinders work independent] y, each as a simple engine taking live steam, the doublepointed arrows also representing the exhauststeam,- and there being no steam which has expanded when the engine is worked in this manner.

I am aware that prior to my invention compound direct-acting engines have been made having a high and a low pressure cylinder arranged tandemwise, or in line with each other, the low-pressure'cylinder being fed with steam through the exhanst-passage ot' the hi gh-p ressure cylinder, the said exhaust-passage normally forming the inlet-passage for the lowpressure cylinder, the low-pressure cylinder being also fed through an independent inlet-- passage communicating directly with the boiler, such as shown in United States Patents Nos. 186,539 and 176,938; but the high-pressnre cylinder in such engines does not have an exhaust passagc independent of the inlet-pas sage to the low-pressure cylinder.

I claim- A duplex compound direct-acting pumping engine composed of two pairs of high and low pressure cylinders arranged tandemwise, or in line with each other, a main inlet and a main exhaust-passage for the said engine, an ex" haust for each high-pressure cylinder, connected to and forming the inlet for its cooperating low-pressure cylinder, an independent inlet for each low-pressure cylinder, and an exhaust-pas age for each higlrpressure eyl inder independent of the inlet-passage to the low-pressure cylinder, combined with valves located in said independent passages, and in the exhaust-passage for the high-pressure cylinders, whereby the exhaust from each high pressure cylinder may be cut oil from its cooperating low-pressure cylinder and conveyed away, and the actuating-fluid at initial pressure be admitted to the lmwpressure cylinder, substantially as described.

In testimony whcreofl have signed my name to this specification in the presence of two subscribing witnesses.

ALBERT F. HALL.

Witnesses:

F. L. EMERY, B. J. NoYEs. 

